Gotta say I’m agreeing strongly with Jakob’s findings in regard to ‘non-web’ documents in the web browser. Users are accustomed to a different set of controls —a different user agent altogether— when dealing with PDFs, Word documents, or spreadsheets, and are easily startled when these formats are displayed in the browser window as if they were ‘just another web page’. Web page goes in web browser, PDF goes in Acrobat, Word document goes in Word. Who would mess with something that simple? Well, Adobe and Microsoft would. Go figure.

The solution? Pop these non-web-natives open in a new window with minimal chrome, so when the user hits the ‘X’ button instead of ‘Back’ (believing they’re in a specialized program, not the web browser) they won’t lose their original browser window. It makes sense. The sad part is that this is a guideline created to work around somebody else’s colossally stupid design decision: namely the decision to view PDFs, Word documents, and spreadsheets in the browser window at all. But don’t worry: if you aren’t using Internet Explorer, chances are you aren’t suffering this lousy design.

…which is where the guideline falls flat on its ass.

Using Firefox —or any non-IE browser, really— clicking a link to a .doc file will download the file, not view it. So if, thanks to Nielsen’s handiwork, my clicking pops open a new window just to facilitate this downloading, I’m going to be unhappy. And with everyone well aware of what my stance is toward Internet Explorer, you can tell I don’t give a fig if its users get a lousy user experience. They’re already getting one, ignore the guideline.

This whole ‘view it in the browser instead of a dedicated app’ business is something Mac OS X browsers have been blessedly free of, at least until 10.4, when inline PDF viewing became a ‘feature’ of Safari. Curses. By cutting out the Preview.app middleman, Apple has saved Joe User from complications like a toolbar, a paginated preview drawer, the ability to search the document, keyboard shortcuts like zoom, and many more. Oy.

Thankfully this can be overcome with a little Terminal work to restore Safari’s PDF-handling to its former sensible state: